Grenades comprising a booster and similar devices to be launched by a firearm



3,140,669 GRENADES CQRQRESENG A BOGSTER AND SHMILAR DEVICES TO BE LAUNQHED BY A FIREARIW Giulio Wyser, Geneva, Switzerland, assignor to Brevets Aero-Mecaniques S.A., Geneva, Switzerland, a society of Switzerland Filed Nov. 26, 1962, Ser. No. 239,880 Claims priority, application Luxembourg Dec. '7, 1961 3 Claims. (Cl. ISL-65.2)

The present invention relates to special projectile provided with auxiliary propelling means of the rocket type intended to be launched by a firearm intended normally to fire a bullet or similar ammunition (hereinafter called normal ammunition), launching of such a special projectile being effected by means of a special launching charge contained in an ammunition (hereinafter called special ammunition) which is a blank, that is to say does not comprise a projectile, intended to fit in the cartridge chamber of the firearm, instead of the normal ammunition, when it is desired to launch a special projectile. The invention is more especially, but not exclusively, concerned with self-propelling grenades to be launched by means of a rifle, and in particular an automatic or semi-automatic ride.

The chief object of the present invention is to provide a special projectile of the above mentioned type which is better adapted to meet the requirements of practice than those known up to this time, in particular concerning the safety of the rifieman in the case Where the latter making, by mistake, use of the normal ammunition, instead of the special one, for launching a special projectile.

The invention consists chiefly in providing, rearwardly of the war head, and between it and the auxiliary proelling means of the rocket type with which the projectile is fitted, a protective shield adapted to absorb the residual kinetic energy of a bullet fired by mistake in the firearm, which bullet has already lost a portion of its kinetic energy when passing through the axial throat of said auxiliary propelling means in View of the fact that the throat of said nozzle is of a diameter smaller than that of said bullet.

A preferred embodiment of the invention will be hereinafter described with reference to the appended drawing, given merely by way of example, and in which: the only figure is a side view, with parts cut away, of the rear portion of a grenade made according to the invention and shown as mounted on the muzzle brake, acting as a grenade launcher, of the gun.

The following description will relate to the case of a grenade having auxiliary propelling means (also called booster means) provided with an axial nozzle, said grenade being intended to be launched by means of a gun which is either automatic or semiautomatic, after fitting of a launching sleeve 1, secured to the rear of the war head 2 of the grenade, on a grenade launcher 3 (which may act as a muzzle brake) carried by the front end of the barrel 4 of the gun.

This grenade is of any suitable general construction, for instanoe that shown by the drawing and according to which the launching sleeve 1 is provided, at its front end, with a casing in serving to secure it to the War head 2 and also forming a chamber for an auxiliary propelling device (or booster) of the rocket type.

This auxiliary propelling device comprises among other elements, on the one hand an axial propelling nozzle 5, the throat of which is of a diameter smaller than the caliber of gun 4 and, on the other hand, a propelling powder charge 6 preferably in the form of a cylindrical sleeve of an external diameter a little smaller than the inner diameter of casing in, the axial channel 7 limited by said sleeve 6 preferably having a diameter greater than that of the throat of nozzle 5:

If things were arranged as above stated, a serious accident would risk occuring if the rifleman used by mistake a normal ammunition, Le. a bullet ammunition for launching a grenade. As a matter of fact, in this case, said bullet, after having forced its path of travel past the throat of nozzle 5, and after having ignited propelling charge 6 (which is not dangerous in itself) would still have a residual kinetic energy suflicient to produce, by its impact against the rear end of war head 2, the bursting of said head while the grenade is still carried by the end of the barrel 4 of the gun.

The main feature of the invention has for its object to reduce this danger.

According to this feature, the grenade made as above described further comprises a protective or shield armor element 8 located between war head 2 and the propelling charge 6 of the booster, said shield element 8 being capable of absorbing the residual energy of a bullet fired by mistake While the grenade is in launching position.

For instance protective plate 8 may be a metallic circular plate of chromium-molybdenum steel tempered and reheated and having a resistance ranging from to kgs./mm.

Preferably the central portion of this plate 8 carries a frusto-conical projection 8a extending toward the rear, the thickness of this projection being for instance 8 mm. in the case of a grenade to be launched by means of a gun of the above mentioned type.

Advantageously such an armor plate 8 bears against a shoulder 1b turned toward the front and provided in casing la.

It suflices, in order to secure armor plate 8 in position in casing la, to screw in the front portion of said casing in, a locking piece which may be constituted by the rear screw-threaded portion 2a of war head 2, or, still better, by a plug 9 secured in the front portion of casing 1a by said portion 2a of war head 2.

In this last case said plug 9 is preferably made of aluminum or aluminum alloy, and it cooperates with armor plate 8 through conical surfaces, in order to improve the gas tightness of the chamber in which powder cake 6 is housed.

In a general manner while the above description, discloses what is deemed to be a practical and etficient embodiment of the invention, the present invention is not limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the invention as comprehended within the scope of the appended claims.

What I claim is:

l. A projectile to be launched by a firearm intended normally to fire a normal ammunition, this projectile being intended to be launched by a blank ammunition fired by said firearm, this projectile comprising, in combination, a war head, a tubular casing coaxial with said War head permanently secured thereto at the rear thereof and adapted to fit on the front end of the barrel of said firearm, the front end of said casing forming a combustion chamber at the rear of said War head, an axial rearwardly directed nozzle secured to the rear end of said chamber to form the outlet thereof, said nozzle being constantly freely open, said nozzle having a throat of a diameter smaller than the caliber of said firearm, a charge of propelling powder in said chamber, and a circular shield capable of resisting the impact of a normal ammunition bullet permanently secured between said combustion chamber and said war head to form the front wall of said chamber, said chamber containing a central coaxial aperture for allowing said bullet to pass therethrough.

casing frontwardly of said shield between it and the rear face of said war head and having a frusto-conical edge adapted to cooperate with the frusto-conical front edge of said shield to apply it tightly against said shoulder.

References Cited in the file of this patent UNITED STATES PATENTS 3,064,381 Vilbajo Nov. 20, 1962 

1. A PROJECTILE TO BE LAUNCHED BY A FIREARM INTENDED NORMALLY TO FIRE A NORMAL AMMUNITION, THIS PROJECTILE BEING INTENDED TO BE LAUNCHED BY A BLANK AMMUNITION FIRED BY SAID FIREARM, THIS PROJECTILE COMPRISING, IN COMBINATION, A WAR HEAD, A TUBULAR CASING COAXIAL WITH SAID WAR HEAD PERMANENTLY SECURED THERETO AT THE REAR THEREOF AND ADAPTED TO FIT ON THE FRONT END OF THE BARREL OF SAID FIREARM, THE FRONT END OF SAID CASING FORMING A COMBUSTION CHAMBER AT THE REAR OF SAID WAR HEAD, AN AXIAL REARWARDLY DIRECTED NOZZLE SECURED TO THE REAR END OF SAID CHAMBER TO FORM THE OUTLET THEREOF, SAID NOZZLE BEING CONSTANTLY FREELY OPEN, SAID NOZZLE HAVING A THROAT OF A DIAMETER SMALLER THAN THE CALIBER OF SAID FIREARM, A CHARGE OF PROPELLING POWDER IN SAID CHAMBER, AND A CIRCULAR SHIELD CAPABLE OF RESISTING THE IMPACT OF A NORMAL AMMUNITION BULLET PERMANENTLY SECURED BETWEEN SAID COMBUSTION CHAMBER AND SAID WAR HEAD TO FORM THE FRONT WALL OF SAID CHAMBER, SAID CHAMBER CONTAINING A CENTRAL COAXIAL APERTURE FOR ALLOWING SAID BULLET TO PASS THERETHROUGH. 